Imprinting carbon-master set



March 7, 1967 J. KEEN IMPRINTING CARBON-MASTER SET Filed 00*: 11, 1965STATE ADDIQESS A B c co. STREET CITY FIG. 3

FIG 2 INVENTOR. W352 flz-A (commonly known as 3,307,478 IMPRINTIN GCARBON-MASTER SET Joseph Keen, Bronx, N.Y., assignor to Repeat-O-TypeStencil Manufacturing Company, Inc., Wayne, NJ., a corporation of NewYork I Filed Oct. 11, 1965, Ser. No. 494,771 2 Claims. (Cl. 101--149.4)-

facing relation to each other such that upon the application of printingon the front face of the master sheet a carbon mirror image thereof isreproduced on the rear face of this master. This rear face of the masterwith said carbon reproduction of text and the like is employed, in awell understood and known manner, as an imprinting master.

Consistent with the foregoing functioning of carbonmaster imprintingsets, it is broadly an object of the present invention to provide animproved set wherein the reproduction of inadvertent markings on themaster sheet is minimized Without interfering with the effective andefficient reproduction of intended text or markings on said master sheetrear surface. Specifically, it is an object to provide a carbon-masterset wherein heavy pressure printing is effective in preparing saidmaster sheet for imprinting, but light pressure marking such asgenerally characterizes inadvertent marking of the master sheet is notreproduced on the master sheet rear surface.

The above brief description, as well as further objects, features andadvantages of the present invention, 'will be more fully appreciated byreference to the following detailed description of a presentlypreferred, but nonetheless illustrative embodiment in accordance withthe present invention, when taken in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a plan view of an imprinting carbon-master sheet setdemonstrating features of the present invention;

FIG. 2 is a fragmentary plan view of the interleaf sheet of said setwhich illustrates in detail the construction and nature of suchinterleaf sheet; and

FIG. 3 is a sectional view, on a greatly enlarged scale, of thecomponent sheets of said imprinting carbon-master sheet set.

Reference is now made to the drawings wherein there is shown anintegrated imprinting sheet arrangement 10 which is substantiallyidentical to currently available socalled spirit carbon master sets withthe exception that there is included an improvement in the form of anovel interleaf sheet 12. The integrated arrangement of sheets or set 10is of the type which is employed with so-called ditto duplicatingmachines such as is available from Ditto, Inc., of Chicago, Illinois, aswell as being employed in other and similar type of duplicatingequipment. Consistent with the contemplated use in such duplicatingequipment, the set 10 includes a master sheet 14 having a front and rearface 14a, 14b respectively, Which is placed in condition to be utilizedas an imprinting master. This is accomplished by direct printing ofwords and other materials, herein collectively designated 16, on thefront face 14a of the master sheet 14, as well as by direct typing ofmaterial 18 on this master sheet surface. In both instances, thisresults in the printed or typed material being reproduced backward, asat 20, on the rear sheet surface 1412. As is generally understood, thereproduc- United States Patent f 3,307,478 Patented Mar. 7, 1967 tion ofthe printing 20 is achieved with so-called spirit blue dye, analcohol-soluble triphenylmethane dye commonly used in the manufacture ofcarbon paper and readily transferable to other paper surfaces by beingplaced against these paper surfaces and subjected to pressure.

As is further generally the practice, this dye which produces theprinting 20 is provided as a surface coating 22 on a backing sheet 24which is connected along an upper edge 26 to the master sheet 14. Thus,the surface coating 22 of this transfer dye and the imprinting surface14b of the master sheet 14 are in facing relationship to each other inthe conventional arrangement of the set 10. In accordance with thepresent invention an interleaf sheet 12 formed of a tissue papercommonly known as mimeograph stencil tissue and commercially availablefrom numerous sources (e.g. C. H. Dexter & Sons of Windsor Locks, Conn.)is employed in an interposed position between the master sheet surface14b and transfer dye coating 22 in order to maintain the surface 14bclear of inadvertent markings, all as will be subsequently explained ingreater detail. The material of construction for the interleaf sheet 12is also sometimes known by the Japanese designation of Yoshino paper andis commonly used in the manufacture of porous tea bags. For presentpurposes it is to be understood that as used herein and as used in theclaims hereof the interleaf sheet 12 is socalled mimeograph stenciltissue formed from a material of construction, such as a blend of manilahemp fibers and coniferous wood fibers of a basis weight ofapproximately 6.60 lbs. (24 x 36480) and which is characterized by beingof a highly absorbent nature. This absorbent character may result fromthe construction of the paper with said hemp and coniferous individualfibers 28 which are well known to be of an absorbent character. Inpractice when printing or typing 16, 18 is produced under pressure onthe master sheet front surface 14a, this results in the application of alocalized pressure in the form or shape of the letters of the printedtext being applied through the master sheet 14 and through the fibrousbody 28 of the interleaf sheet 12. against the transfer dye surfacecoating 22 of the backing sheet 24. Under these circumstances, theabsorbent interleaf sheet 12 functions to accept the transfer dye fromthe surface coating 22 and transmit this dye, as by soaking, through thefibrous body 28 thereof through to the surface which is in physicalcontact with the master sheet surface 14b. Thus, the transmittedtransfer dye is applied as printing 20 to the surface 141; of the mastersheet 14. In this manner a mirror image of printing 18 is reproduced asbackward printing 20 on the surface 14b of the master sheet 14 eventhough the interleaf sheet 12 is never removed from an interposedposition between the master sheet surface 14b and transfer dye surfacecoating 22.

From the foregoing it should be appreciated that the absorbent interleafsheet 12 is effective to prevent inadvertent dye transfer from thesurface coating 22 to the master sheet surface 1415 while notinterfering with or preventing intended dye transfer. Such intended dyetransfer which results from heavy pressure printing 18 being applied onthe front surface 14:: of said master sheet 14 is effectively appliedright through the interleaf sheet 12 while inadvertent light pressuremarking on the master sheet surface 14a is not. The use of saidabsorbent interleaf sheet 12 is thus an improvement over the use of agenerally non-absorbent interleaf sheet of prior art imprinting sets.Such prior art interleaf sheets as are now relied on to protect themaster sheet surface 14b require removal from this protecting positionduring the application of printing or typing 16, 18 in order to permitthe printing 20 to be effectively reproduced on the master sheet surface14b. If numerous printing or typing operations are performed on the set10 in preparing the master sheet 14 for imprinting, as is generally thecase, in each instance the prior art non-absorbent interleaf sheet mustbe removed prior to such printing and then placed back in positionfollowing this printing operation. In contrast, the absorbent interleafsheet 12 of the present invention is left in position at all timesbetween the master sheet 14 and backing sheet 24.

A latitude of modification, change and substitution is intended in theforegoing disclosure and in some instances some features of theinvention will be employed Without a corresponding use of otherfeatures. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the spirit and scopeof the invention herein.

What is claimed is:

1. A method of preparing a master sheet for imprinting, said mastersheet being included in an arrangement of sheet material; saidarrangement including in addition to said master sheet a backing sheethaving a coating of a transfer dye in facing relation to said mastersheet and an interleat mimeograph stencil tissue sheet of an absorbentcharacter in an interposed position between said master sheet and saidcoated backing sheet, said method of preparing said master sheet forimprinting comprising the steps of printing on said master sheet withsufficient pressure and causing the transfer dye, in response to saidpressure, to soak through said interleaf mimeograph stencil tissue sheetonto said master sheet.

2. An improved method of preparing a master sheet for imprinting asdefined in claim 1 wherein said transfer dye on said backing sheet isspirit blue.

References Cited by the Examiner UNITED STATES PATENTS 2,372,918 4/1945Vickery M 101-149.40 X

ROBERT E. PULFREY, Primary Examiner.

I. A; BELL, Assistant Examiner.

1. A METHOD OF PREPARING A MASTER SHEET FOR IMPRINTING, SAID MASTERSHEET BEING INCLUDED IN AN ARRANGEMENT OF SHEET MATERIAL; SAIDARRANGEMENT INCLUDING IN ADDITION TO SAID MASTER SHEET A BACKING SHEETHAVING A COATING OF A TRANSFER DYE IN FACING RELATION TO SAID MASTERSHEET AND AN INTERLEAF MIMEOGRAPH STENCIL TISSUE SHEET OF AN ABSORBENTCHARACTER IN AN INTERPOSED POSITION BETWEEN SAID MASTER SHEET AND SAIDCOATED BACKING SHEET, SAID METHOD OF PREPARING SAID MASTER SHEET FORIMPRINTING COMPRISING THE STEPS OF PRINTING ON SAID MASTER SHEET WITHSUFFICIENT PRESSURE AND CAUSING THE TRANSFER DYE, IN RESPONSE TO SAIDPRESSURE, TO SOAK THROUGH SAID INTERLEAF MIMEOGRAPH STENCIL TISSUE SHEETONTO SAID MASTER SHEET.